Damper.



0. IV]. DAUGHERTY.

DAMPER.

APPLICATION FILED APR. 18. I911.

Mfifififil$ Patented pr. 20, 1915.

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STATE PATENT @FFUE.

OTTO MATILE DAUGHERTY, OF ST. PAUL, MINNESOTA, ASSIGNGR TO AUTOIMCATIC HEAT REGULATOR 00.,

OF ST. PAUL, MINNESOTA, A. CORPORATION.

DAMPER.

Application filed April 18, 1914.

To all whom it may concern Be it known that I, OTTO M. DAUGHERTY, citizen of the United States, resident of St. Paul, county of Ramsey, State of MlIlIl6- sota, have invented certain new and useful Improvements in Dampers, of which the following is a specification.

The object of my invention 1s to provlde a damper operating automatically with the suction through the flue to close or open the passage through the flue proportionately to the strength of the draft.

The invention consists generally in various constructions and combinations, all as hereinafter described and particularly pointed out in the claims.

In the accompanying drawlngs forming part of this specification, Figure 1 is a sectional view of a damper and flue embodying my invention, Fig. 2 is a transverse sectional view, through the flue, looking down on the damper, Fig; 3 is a detail sectional view of the locking device for holding the damper in its open position.

In the drawing, 2 represents a flue of ordinary construction and 3 is an arm supported by pivots 1 that are mounted 111 cars 5 which project outwardly from a plate 6 secured to the wall of the flue. An arm 3 projects through a slot '7 in the flue and is provided with an inner end 8 bent at 'r1ght angles substantially to the mlddle portion of the arm and to which the damper blade 9 of I suitable outline to conform to the shape of the pipe, is secured. This blade is made of thin material for the purpose of economy and for ease of operation of the damper, and to stiffen the blade I provide a brace rod 10 extending across the blade from side to side and to prevent soot and ashes from lodging between this rod and the blade I prefer to bend the edges of the blade upwardly, as indicated at 11, and mount the ends of the rod 10 in these bent portions of the blade, thereby bracing the damper and at the same time providing a smooth surface on each side thereof to which the soot and ashes will not cling to any appreciable ex tent. The outer end of the arm 3 is threaded and provided with the usual counter-balance weight 12, capable of adjustment back and forth to regulate the movement of the damper. Between the ears 5 I arrange a slide 13, vertically movable between guides 141 and having an arm 15 at its upper end Specification of Letters Patent.

Patented Apr. 2, 1915. Serial No. 832,690.

that is adapted to engage a tooth 16 formed on the upper surface of the arm. The end of the arm is bent, as shown in Fig. l, to present a square face to the tooth and limit the upward tilting of the arm during the automatic movement of the damper toward the face of the arm, and the tooth is so formed that the arm will not slide over the tooth and automatically lock the damper in its open position until the arm is struck up by the hand of the person using the damper. In other words, there will be no opportunity for the damper to become accidentally locked in its open position, but whenever desired, it may be locked by striking the arm 3 with sufiicient force to carry the tooth past the bent end of the locking arm 15. When this has been done, the locking arm will engage the outer face of the tooth l6 and positively hold the damper in its open position, regardless of the draft through the flue. A finger grip 17 is provided on the lower end of the slide and by raising this slide upwardly the operator can disengage the locking device and allow the damper to again become automatic in its action. I also prefer to press a stop 18 out of the slide 13 to project into the path of the arm 3 and limit the downward swinging movement of the outer portion thereof.

A device of this kind is frequently used in a pipe that is oval, substantially, in cross section at one end, while at the other it is desirable to join it with a pipe that is circular in cross section. The bending of the pipe walls to fit the circular pipe might result in cramping or binding the damper and I therefore prefer to provide a ring 19 fitting within the pipe and seated in the groove on the corrugation 20, ordinarily found in pipes of this kind, and operating to brace and strengthen the walls of the pipe and prevent them from being bent out of form to the extent that the damper would be prevented from swinging freely under the pressure of the draft.

In various ways the details of construc tion herein shown and described may be modified and still be within the scope of my invention.

I claim as my invention:

1. A. damper blade having end portions thereof inwardly curved to conform to the curvature of the walls of a flue, a rod having its ends mounted in said end portions per blade,

arm pivoted thereon and projecting therein,

a damper blade mounted on said arm Within said flue, a counter-balance carried by said arm, said arm having a tooth thereon and a locking arm having a part to engage said tooth and lock said arm and blade in.

their open position, said locking arm being normally inoperative and permitting the automatic tilting of said damper arm under pressure of the draft in said flue, for the purpose specified.

3. The combination, With' a flue, of an arm pivoted therein, a damper blade carried by said arm Within said flue, a counter balance for said blade, said arm having a tooth formed thereon, and a slide having a part to normally contact with one face of said tooth and limit the movement of said damthe engagement of said part with the opposite face of said tooth when said Copies of this patent may be arm is tilted past a predetermined point locking said blade in its open position.

l. The combination, with a flue, of a pivoted arm, a damper blade supported by said arm within said flue, a counter-balance for said blade, said blade being free to swing under pressure of the draft in said flue, and a locking device operating to hold said blade in its open position when said arm is tilted by hand past a predetermined point.

5. The combination, with a flue, of a pivoted arm, a blade mounted thereon, within said flue, a counter-balance for said blade, said arm and blade being free to swing under the pressure of the draft in said flue, a locking device operating to normally limit the swinging movement of said blade toward an open position, said locking device becoming automatically operable to positively lock said blade in its open position when said arm is tilted by hand past a predetermined point.

In witness whereof I have hereunto set my hand this l lth day of April, 1914-.

OTTO MATILE DAUGHERTY.

\Vitnesses Miss E. DAHLMAN, E. C. GRIERSON.

obtained for five cents each, by addressing the Commissioner of Yatents,

Washington, D. C. 

